Modeling solitary wave propagation and transformation over complex bathymetries using a two-layer Boussinesq model

Solitary gravity waves play a key role in the field of coastal and ocean engineering. The two-layer Boussinesq model developed by the authors has excellent linear and nonlinear properties. However, the permanent solitary wave solution and the numerical performance of the model in describing the solitary waves over complex bathymetries remain unknown. This research addresses this issue by conducting numerical simulations. The test cases include high amplitude solitary wave propagation over a constant water depth, shoaling of a solitary wave over a slope, and reflection of a solitary wave from a truncated composite plane beach. New experiments for solitary wave propagation and transformation over two submerged breakwaters are also presented. The computed results are compared against the analytical solutions and experimental data, with more attention given to the interior kinematics. Excellent performance is obtained, and the model shows significant improvement over traditional Boussinesq-type models. A detailed comparison between model predictions and laboratory data/analytical solutions is given for each case. •The simulation of solitary wave travels over complex bathymetries using highly accurate two-layer Boussiensq model is reported.•New experiments for solitary wave propagation and transformation over double submerged breakwaters are conducted.•More attention is given to the interior kinematics.•The excellent agreements with analytical solutions and experimental data are obtained.